Pneumatically operated swab plunger



Oct. 31, 1933. E. K. wATTERs PNEUMATICALLY OPERATED SWAB PLUNGER Filed April 3, 1953 INVENTOR W ATTORNEY Patented Oct. 31, 1933 PNEUMATICALLY OPERATED SWAB PLUNGER Egbert K. Watters, Houston, Tex., assignor to Hughes Tool Company, Houston, Tex., a corporation of Texas Application April 3, 1933. Serial No. (i64,1 34

6 Claims.

My invention relates to swab plungers to be employed in plunger lift devices wherein the plunger is operated by pneumatic pressure.

In the operation of plunger lift devices the plunger is raised with its load of liquid from the bottom to the upper end of the eduction tube by pneumatic pressure. The plunger drops back by gravity to the bottom. In the usual arrangement the plunger does not drop as rapidly as is desired, forthe reason that the passage through the plunger is not large enough to permit the free flow therethrough of fluid in the tube. In other words the plungerpresents too great an area against which the resistance of the fluid may I act to impede the dropping of the plunger.

It is an object of my invention to provide a plunger with a minimum of surface presented to the fluid in the well to resist its free movement downward in falling.

I desire to speed up the downward movement of the plunger by leaving the interior of the body of the plunger open to permit the passage therethrough of the fluid in the well.

In the drawing herewith Fig. 1 is a central longitudinal section through the lower end of the eduction tube with my plunger therein.

Fig. 2 is a transverse section on the plane 2--2 of Fig. 1.

The eduction tube 1 is to be understood as extending from the surface down to the pumping depth in the well. The lower end has a cap 2 which closes the extremity of the tube except for an axial opening 3 therein to allow entrance of the well fluid.

A stop member 4 is housed in the cap and adapted to slide vertically therein. It comprises an annular block the upper end of which is tapered upwardly somewhat to provide a sloping surface 5 upon which the plunger '7 may engage. There is a fluid passage 6 centrally of the block. A coiled spring 8 holds the stop member upwardly against the lower end of the tube 1 and furnishes a shock absorber for said plunger.

The plunger 7 fits slidably within the tube and is cylindrical on its outer surface. On the interior of the plunger the wall at one side is thickened somewhat at 9 to house the valve member 10. This wall 9 tapers in thickness from about midway of the plunger to the upper end thereof and is of approximately uniform thickness from the midway point down to the lower end of the plunger. There is a downwardly presented valve seat at 11 and the valve is pivoted below said seat.

Said valve is a flat disc, having a stem 12 thereon hinged at 13 in a recess in the wall 9. There is a depression in the wall at 14 to receive the valve when it is swung downwardly out of the passage 15 through the plunger. When in open position the valve is inclined slightly outward at its lower end and will be held in that position by the passage of the plunger through the fluid.

I provide a valve actuating rod 16 which projects upwardly through a bore 1'7 in the wall 9 and has its reduced upper end held normally in contact with the open valve. The lower end of the rod projects a short distance below the lower end of the plunger and said lower end of the plunger is beveled inwardly at 19 to engage the surface 5 on the stop member and to permit contact of the rounded lower end 18 of the rod against said stop. Said rod is limited in its sliding movement by a key 20 extending into the recess 17 and engaging in a keyway 21 in the rod. A spring 22 in the recessl'? normally holds :said bolt at the lower end of its movement.

When the plunger drops to the bottom the valve will be open and a free open passage through the plunger is provided. When it strikes the stop member 4 the rod 16 will be thrown upwardly and, by engaging the valve, will throw it into closed position so that fluid flowing upwardly in the tube will hold it closed.

I The pressure fluid, air or gas, below the plunger will lift the plunger, with its load of liquid above it, to the surface in the usual manner and the valve will be opened at the upper end of the stroke of the plunger so that the plunger may again fall.

The invention allows the plunger to fall freely. There is little resistance to the falling movement and the speed of operation will be accelerated as is desired.

'What I claim as new is:

1. A pneumatically operated swab plunger including a cylindrical tubular body having a longitudinal passage, a thickened wall on one side of said passage, a valve seat intermediate the ends of said pasage, and a valve housed in said thickened wall and adapted to swing upwardly into said seat.

2. A pneumatically operated swab plunger including a cylindrical tubular body having a fluid passage therethrough, a valve seat intermediate the ends of said passage, a valve below said seat and hinged in the wall of said plunger, said valve when open being inclined downwardly and outwardly, and means to move said valve toward closed position in said seat.

3. An eduction tube, a swab plunger movable the full length of said tube, a stop at the lower end of said. tube, said plunger having a fluid passage therethrough, a valve seat intermediate the ends or" said passage, a valve disc hinged in said passage below said seat and adapted to be swung upwardly into said seat, and means in said plunger adapted to engage said stop to open said valve.

4. In a plunger lift device, an eduction tube,

stop member therein, a plunger in said tube above said stop, said plunger being of tubular construction with a fluid passage therethrough,

a downwardly presented valve seat in said pas-- sage, 'a valve disc housed in the wall of said passage, said valve when open being clear of said passage, and means operated by contact with said stop member to close said valve.

6. A swab plunger shaped to fit within an educ-' tion tube and having a passage therethrough, a valve seat intermediate the ends of said passage, a valve disc hinged in the wall of said passage and adapted to be swung upwardly into said seat, said valve when open being inclined outwardly at its lower end, and means actuated at the lower end of the stroke of said plunger to move said valve into said passage and swing it to its seat.

EGBERT K. WATTERS. 

